US2176949A - Page and line synchronizing apparatus - Google Patents

Description

IOct.' 24, 1939. v

Filed March 26, 1937 2 Sheets-Sheet l ,4v/WER ca/L C BUCK 2o 2/l +3 l I z I l", VAAAV., i

' L I: m/Nrskco/L ul1: 25 /wH/re 2 I 5f? 1:' 26 E f faune/miur b 23 HWENTORY 29 MAUR/cf Aerzr `TTORNEY gence tobe transmitted'is scanned line byline v.Patented 24,"1939 UNITED' STA-'res f race Ann um: srNcnnnNlzrNa A marinus,

'PATENf-r ori-lele 4Maurice' Arm, N. Lucanor te Radio off'America, n muon of Delaware Application Much ze, isst, serai No. 133,135 9 mim (ci. 11a-sas) My invention relates broadly to synchronizing apparatus, and more particularly to line andv page framing apparatus adapted for use with facsimile or photoradio machines. i

In the so-called facsimile or photoradio transmission of intelligence, -a picture of the intelliby scanning apparatus which interprets the variations in optical density along the lines sequentially', and these representative' variations are transmitted to `receiving apparatus. Accord-A ingly,.it is necessary that the material on which the received intelligence is to be 'recorded be maintained at all times in synchronism with the transmission apparatus or else a distorted or unintelligible representation is obtained. The material which is transmitted is usually a single picture whereas at the receiving apparatus the received intelligence is recorded on afreproducing material which is usually quite lengthy and is rolled upion the machine in the form of a long roll. `This being the case, it is necessary to identify both the position of .the page at the. transmltter, that is to say, the start of the picture which is transmitted, and it is also necessary to identify properly the position on the particular line which is transmitted. Hence, it is an object of this invention to provide page and line framingapparatus which will maintain the receiver in a synchronized relationship with the 'transmitter from which it is receiving intelligence.

It has been found from practical. experience vthat the roll of material on which the intelligence is reproduced, which is usually paper, is

' subject to variations in length with temperature,

weather conditions, etc.' It is also customary to provide advertising material on the back of the sheet upon which the intelligence is recorded and as a result when a single complete picture orrepresentation is removed, unless some meansl is provided for exactly identifying the beginning oi!l the position at which the 'epresentation is to berecorded, the result will ithat the advertising material on the back will be entirely out of line with the recorded material on the front of the'paper. Therefore, it is an object o! my in- .vention to provide a lframing apparatus in which sheet-'spacing on one side of the recording mate-` rial maybe maintained in accurate and definite Y relationship with the ,material Y recorded .on the recordingI surface on the i'r'ont oi.' the sheet.

siicthc recording material is fedv through l the machine by frictionlfeed, there is also the possibility that the paper `may slip, 'that is Iicy,

l of the powercircuit an the feed may not be absolutely constant and as a result this would also tend to disalign the printed material on the back of the sheet and the recorded material on the front and, accordingly, it

yis another object-A of my invention to provide f 5 Yapparatus by which this is rendered impossible.

Again, the user may nd it necessary at times to switch off at a time when only a portion of the picturehas been recorded(` It |this is done,

under ordinary circumstances,the machine 10 would immediately stop andi disalignment of the l printed materialen the bacloi vthe recording sheet in so far as the received material was con-'- cerned would result since it is-contemplated that this material would be stricken from the machine 15 in complete unit sheets. Therefore, it isV another object of this 'invention to provide a device Vwhereby the machine will automatically assume the correct framing position upon the breaking will then stop.

It is also not only possible but probable tha the person using the machine may switch on or start to operate the machine at a time which is not coincident with the beginning of a picture from the transmitter. 1f the machine immedl- $5 ately began yto operate under these circumstances, then again disalignment voi theprinted material and the recording material in sofar as a sheet arrangement is concerned would result. It is therefore another object oi! my invention to pro- 0- is to say, the transmitter and receiver were out Vol! line synchronizingy position.4 Accordingly, it 40 is another object oi my invention to provides synchronizing apparatus by means oi which the receiver may be drawn intocorrect line relationship with {the transmitter in response to line synchronizing signals from said transmitter. 45 \In general, the operation of the-,deviceis as follows: Immediately prior to the oi' the transmission of a picture at the transmitter'.

a steady impulse is transmitted for a short time period, which in practice has been found usually d0 to be oi the order o! .thirty seconds. This steady signal comprises the page framing impulse and is Ttransmitted insofar aslthe picture is concerned in a direction usually voppositetothe. line vsyn-- chronizlng signal and, negeagein, a im bem usl found satisfactory from an .operation viewpoint to transmit this signal in the so-called .`white.

direction. Means are provided which are responsive to the signal to complete initially the energizing circuit of thedriving motor -of the machine. A signall of less than the predetermined time duration, suggested herein as'thirty seconds, will not result in response by the mapulse signal is sent out from the transmitter when the transmitter scanning drum is at a definite position with vrespect to the scanning pickup apparatus. Therefore, the transmitted ship tothe angular position of both the transmitter and the receiver drum since the receiver is to be maintainedin synchronous relationship and in. co-phasal-vcondition with respect to the sponding to the page'framing signal, herein assumed thirty seconds duration, then means are provided whereby the machine is conditioned to be responsive to the line. synchronizing signals, and unless thecomplete page frame signal is transmitted, no .receiver actuation will result. At the end of the line synchronizing signals the machine is automaticallyrendered non-responsive to any other synchronizing signalswhich might be transmitted either from the desired transmitter or from any other transmitter.

My invention will best be understood by reference to the accompanying drawings, in which- Fig. 1 is the receiver circuit used in conjunction with the apparatus of Fig. 2," f

Fig. 2 shows the synchronizing control apparatus schematically, and

Fig. 3 shows a mechanical delay arrangement.

Referring to Fig. 1, there is shown the diagram with a circuit which is responsive only to the. vassumed thirty-second page framing signal. As vhas been stated, this signal is sent vin a white or positive direction so that applied to the control grid cfa'. vacuum tube in itsnormal direction, it will increase the grid 'potential and hence the output plate current ofthe tube. Aninput circuit IU is joined to the primaries of two transformers iI-and I2. The secondary circuiti 3 `of diodev section of a lduplex-diode-triode tube I 4.

the potential of a control grid of a pentode tube Il. The platev circuit of the pentode I1 is joined to the con la ofthe relay in the une framing device which will be referred to hereinafter in connection withFig..2. Also joined in the plate circult of tne'tube. n 'is the blackpprmtercou is. In the control grid circuitof the duplex-diode- 20, thev latter-being joined in pareuel with` the resistance I I8. One side 'of the resistance I9 is joined tothe cathode of the tube I4,- and thence I, to ground through a resistor 2l.

A portion of the input signal is fed to the. trans'- former I2 and by means of the secondary 22 stated, to the order of fteenseconds. Each lineA line control, impulses bear a definite relationtransmitter. Assuming thatl the machine is rethe transformer I I is joined tothe plates of the The output of the triode section of this tube joins which is developed potentials adapted to control triode tube-II is a resistance I 8 and a condenser i avana thereof thence to the full wave'rectier 23. This rectified signal is fed across-a resistor 24 which is in the control grid circuit of the pentode 2'5.`

The output of the pentode' .25 is fed to the magnetic winding 26 of a chatter relay `and one of the contacts of the chatter relay is grounded, the

other of said contacts being joined to the point of connection of resistance I9 and condenser 20. 'I'he time constants of this latter condenser-resistance combination is comparatively high.

The action of the circuit is as follows: 'Let us4 assume that the thirty second synchronizing signal is not being received but that an'ordinary picture or someother comparatively rapidly varying signal is impressedjon the input circuit Il of this circuit. A portion of this signal will be rectied by the full wave rectifier 23, the control grid of tube 25 will be rendered more positive, and

the chatter relay will be alternately closed and sistance 2l and will be charged by the plate current potential drop across this resistance. As this takes place comparatively rapidly, that is to say, ther chatter relay will open and close fairly t rapidly, the charge on condenser will not have time to leak off' across .resistance I9, and the duplex-diode-triode I4 will be biased to a cut-o3 Y. value. Hence',there will be no current through the starting relay coilor, as it will be referred to hereinafter as the page framing coil.

However, with asteady signal, the rectifier 23 will furnish a steady current which will bias the control grid of tube 25 to a deflnite value and will open the contacts 28, 29 of the chatter relay for a time as long as the duration of the signal.

During this length of time, the charge on conf denser 28 will after a time be dissipated across resistance I9, and accordingly the potential of' the control grid of the tube I4 will' rise past a f* cut-off value and the tube I4 will draw plate current and, accordingly, after an interval depending upon the time constants of the relay, this relay will be actuated due to the current through the coil I8. This has been of thev order of fifteen seconds.

Referring to Fig. 2, there is shown a schematic o arrangement of the actual synchronizing mechanism. Four cams 58, 5I, 52, and 53 are adapted to be driven by the driving motor of the device so that each cam makes a vcomplete revolution in a time interval equal to the time which is necessary to print one page of the intelligence which is.

transmitted. In this particular instance, the time has been of the order of twelve minutes. Cut on the face of each -one of thesey Acams is a cam slot, and the relative spacing of the position of these slots is shown bythe letters A and B. Ad-

jacent the cam 58 is a cam rider 54 which is joined to the amature -of a relay 58, the actuating coil of which isthe callA I8 shown in Fig. l. It will be seen that there are two distinct sets yof contacts adapted to be closed .by this armature,

the slot of cam 5l and opens the contacts 51 v and' at the Sametime closes the contacts 58, these latterfcontactsishorting out the black coil ofthe' printer which will be referred to hereinafter. f

The cam5I which is mounted on the same shaft as cam 58 and accordingly will rotate with equal enema velqcity therewith, vcontains m than:

` armeno nce therein a slot-"B which is spaced behind the pomtion'of the slotl A of cam Il by an amount equal to the width of-slot A, that isto say, the

angular width with `respect to the circumference' thereof. This cam 'has ridingA thereon a rider which is adapted to open and close contacts il,

the face thereof a cam slot A ofthe same width and the same location vrelative to cam Il, that is tosay, the cam rider 1| will fit into the slot A in cam 52 at the'same time that the rider 5I will iit into theslot A of the cam Il. The two slots are of the same angular width with respect to the circumference oi.' the cam. .'The rider 1| is joined to an arm-12 which is adapted to open and close contacts 13 depending upon' whether the rider is riding on the face oi the cam or is iitting into the cam slot thereof. When riding upon the face, the contacts 13 are closed; and when fitting into the slot,.the'contacts`13 are open. The cam Il -is in thesame relative position with respect I to cam 50 as was cam l2, and operating in conjunction therewith is a rider Il, an arm 82, and

'contacts the latter being open when the rider isin the cam slot A, and being closed when the rider. is engaged with the face of the closed cam Il.

The operation of the device is as follows: It will be noted that the armature of relay is adapted to close thecontacts 51, thus completing the driving motor circuit through the contacts Il which are mounted on the rider Bii'which is used in conjunction with cam 5|. Normally, as has been stated when the machine is in a page frame position, the rider lts., into the slot A-oi cam Il, the contacts B1 are open and the motor does notstart evenl though the starting switch has been l'connected unless the armature 51`is lifted out of Y,

the cam slot A of cam 50 and Joins the contacts together. This latter will ,be done only when f thereis current through the colli! of relay 56 and, as has beenv explained hereinbefore with reterence to-ll'ig. 1. this can take place only when a portion oi the thirtyl second page framing signal has been received. This normally closes at the end of about niteen seconds oi' that signal and is held upwardly out oi engagement with the slot and closingthe contactsuntil the cam slotA n. through.- from under the. rider Il which no1-many takes about fifteen seconds. Hence. it

will be seenv that if-thc page; framing synchronizing 'signal isreceived tha-motor circuit iis automatically closed 'and the motor will start, it hav- "ing taken' about A'seconds Lto actuate the M'mature. of the relay, and the remaining fitseconds being used in the'interval necessary,

to take-thence Armin" undertherider u, this rider will then hold'the motor circuit closed nor-` mally 4for a lengthv of time equal toeone complete rotation of .the'cam which is normally twelve minutes from the average vAt the 'end oi that second mteen second interval,the cam il hasthen paued to` the'position where slot B of' thiscam' will be immediately under the rider Il. Now, wheny this latter happens, the motor circuit' would normally be broken. However. it will be noted from the-figure that a iiith cam 9| having a slot C cut in' the face therein is adapted to co-iilerate with a rider Il joined to z the armature l2 of'a relay whose magnetic -coun adsptedtc heactusted hyeurreht from the 4black tube o! Joined to the amature l2.

isapair ofcontacts Il which are closedwhenthe rider is engaged with the upper face of the cam and which are open when the-rider is in the Now, at the end of the page framing synchronizing signal, a series of line synchronizing pulses are sent in the black direction, and each one of these pulses is indicative of the position ofthe scanning drum at the transmitter. Since thecam 8l is mounted directly on the shalt oi the recording drum, the position of the slot C will be indicative of the position of the recording drum. Now, if the recording drum is in correct line framing position a synchronizing pulse will be received when l the rider 8l is directly opposite the cam slot C and the relay will hold the armature, and hence the rider out of contact with the slot and will close synchronizing pulse will be received at a time when the riderl is riding on the face of can1 90, and these pulses being of' short duration, when the rider goes around to the position opposite the cam slot C it will fall into the cam slot, thus breaking the motor energizing circuit for a short period or time or.'in other words. jogging the motor. This 'will take place for a few times until the position of the helix drum oi the facsimile machine on which this device is used is in correct line framing position and the motor circuit ,remains unbroken due to the armature 92- being held at the proper time out of engagement The actionof the cam 52 is as follows: It will be noted that the contacts 13 are arranged in such a position that when they are closed they shortcircuit a switch S in one of the motorvenergizing leads. This cam assures that the machine will always stop in the proper positionto start a new page oi' recording materialwith respect to the printed material which-is printed on the back of the recording roll and which is definitely spaced., A time of twelve minutes approximately has been required in actual practice to transmit one sheet of this material and this corresponds to the time of one complete rotationv of each of the cams through I3 respectively. Now the rider 1| will be engaged in the cam slot A of cam 52 at the same time that the rider Il is engaged with cam slot A of cam I I, and hencewill not be taken out of the ,slot until after the machine has started inresponse to a page synchronizing signal. After the machine has started,- this rider will' shortcircuit the switch S until the cam 52 makes one complete rotation and comes back again to the proper page position with respect to the printed material. Hence,if a user should decide to turn ot the'machine in the middle of a received page ot recording material,v the Amachine will automatically-run luntil it has been properly spaced and will tiren close due to the opening of contacts `13 when the rider 1l falls into the Slot A of ,52.

It has been .notedl inI Practice that the paper rial printed on the back of, this roll will expandl or contract without regard to an actual linearV measurement. As a result. if the full sheet of material were transmitted and another sheet im- 75 Y' rangement through the machine.

4 mediately begun, it would be quite possible that the transmitted intelligence would not match up correctly with printed material such as advertisements on the back of the material and the ed'ect of material printed on`-both sides evenly would.

very shortly be spoiled. As a result, it has been customary to punch the paper with an indicative hole, denitely spaced from the printed material, and it is the function of the cam 53 to control passage of the material in properly spaced ar- At the time when the machine is started due tothe lifting of the armature 54 from the slot A of cam 59, due to their relative positions, the rider 8l willbe lifted from the slot A of cam 53 at an interval some fteen seconds later than the activation of armature 54 due to the rotation of the driving motor and the consequent change in position of slot A.

' Now, when'this rider 8| is forced up outwardly from the slot A, it closes contacts 83 on the arm 82 which are also joined to the power circuit of the driving motor. Connected in series with these contacts is almagnetic coil 95'which is adapted to control'the movement of a soxleno'id arm 96 which is joined-'to a clutch 91, and when current passes through the coil 95 the solenoid retracts one portion of the clutch out of engagement with the other, stopping the paper ifced.

Also in series with contacts 83 are two wiping contacts 98 and 99 between which the recording material, which in this case is paper, passes.

material von the back of the sheet, the clutch will remain in engagement and hence feed the' paper until the contacts`98 and 99 come to an opening in the paper, and when they do, the solenoid arm A' 96 will retract a portion of the clutch 91 from ,thev paper feed and even thoughthe machine keeps' running, the paper will not be fed through. As borders are necessary to the recorded material,

the only result will be a small shortening or lengthening ofthe border dependent on the relative spacing of the'holes in the paper and the actual transmitted intelligence is unaffected.

Now, of course, it may be desired to keep the machine running steadily from one page of transmitted material to the next and, accordingly, it

may be arranged that the page synchronizing signal may send, say, fifteen seconds ahead of the time when cam slot A of cam 50 comes opposite the rider 54. 'I'his will. assure that the armature 55 will be retracted by the relay56 at exactly the time when the cam slot A'passes to the rider 54 and, hence, the rider will be held out of engagement vand there will be no interruption of service.

Referring to Fig. 3, there is shown a mechanical arrangement for effecting the fifteen sec'ond,l

time delay in the starting of the motor of the device in response to the thirty second page framing signal and, therefore, is analogous to the electrical circuit illustrat Y. in Fig. 1. -In this case, the recording drum h s attached thereto a cam A which performs thefsame function las the cam 90 of Fig. 2'. Also attached to the shaft is a cylindrical member G having a detent pin therein which is adapted to strike a pivoted lever arm L,

and thus effecting a movement of the pawlD. In

intimate relationship with the pawlv D is a toothed ratchet wheel E to which is fastened one of a set of contacts F. Itwill be noted that a spring. member normally retains -the ratchet' wheel in a definite position so as to normally space the contacts F apart by a predetermined amount.

Now as the paper is properly punched 'to give correct spatial arrangement with respect to the'printedx Immediately adjacent. the pawl Dis a locked pawl D'. The contacts F are adapted lto short-circuit the contacts on the relay armature'. B. Immediately adjacent both the pawls D and D' is a magnetic core which is adapted to be energized by the page framing signal. v.

The action of the device is as follows: rSince thewindin'g of the electromagneticdevice C is joined tothe black tube, no current will pass therethrough with steady signals-in a white direction. signal is received, and which is a steady signal in the White direction, no current will ilow in the plate circuit of the vblack tube. The scan- .ner drum shaft is rotating at approximately 120 R. P. M. and, as a result, the detent pin will strike the leverarm L twice per second. This willdraw the pawl D' across the teeth of the wheel E `and if, for instance, a -fteen second time delay "is, desired, then the wheel E ,will have thirty .teeth since the'pawl will be actuated .twice per second. -When the. pawl'reaches the top tooth despite any 'continued action by the detent pin, there will be no further turning of thel ratchet E, ,l and in this position thel contacts F are closed. Hence, the paper feed clutch is actuated and the paper begins tofeedy through in correct page fram- As a result, when the page framing ing position.' JNow, if there should be an interruption of the page framing'signal prior to Athe fifteen second interval, due/1 to the pulls in the black direction, the ,black tube output current will flow through-the winding of the'electromagnetic device C, and bothk the locking pawl D' and the actuating pawlvDwill be attracted `to the'core of the device, thus releasing the wheel which will be returned to its normal or starting position due to the action of the spring, and then take a complete steady signal of at least fifteen seconds to start the actuating feed clutch.

What I claim is:

v1. A page and linefraniing' system for. facsimile apparatus whereinpage and line framing signals of predetermined duration are received at selected time periods comprising a driving motor,

means operable upon the receipt of a predeter- 55 2.- A page and line framing system forfacsimileapparatus wherein page and line framing signals of predetermined duration are received at selected time periods. comprising a driving motor,

' means operable upon the receipt of a predetermined portion of said page framing signal to initially complete the driving motor energizing circuit, sad-means comprising a cam mounted in y driven relationship to the driving motor, a cam slot, a cam follower, a relay armature connected to said follower, said relay armature being adapted to-open and close the driving motor circuit, means associated wtih said relay to operate said relay upon receipt of a predetermined portion .of

after the receipt of the complete page framing signal to r'ender operable said line framing means lfor a definite period, said line framing means controlling means -to interrupt the driving motor circuit for a predetermined interval of time upon lthe page framing signal, and means operable only make andbreak an electric switch means in the non-receipt of a line framing signal at the interrupting interval. f

3. In a page and line frame system adapted to respond to page and line synchronizing signals of definite duration transmittedA from transmission apparatus, motor means, means operable upon the receipt of a predetermined portion of said page framing signal to initially complete the driving motor energizing circuit, means operable only after the completion of the aforesaid motor circuit to render operable line framing means for a predetermined time period, said latter means comprising a cam containing a slot extending for a definite portion of its peripheral length and a cam follower, the cam follower being adapted to ldriving motor circuit initially closed by the page l framing signal responsive means.

4. In a page and line frame system adapted to respond to page and line synchronizing signals of .denite duration transmitted from transmission apparatus, motor means, means operable upon the receipt of a predetermined portionof said page framing signal to initially complete the driving motor energizing circuit, means operable only after the completion of the aforesaid motor circuit to render operable line framing means for a predetermined time period, said latter means comprising a cam containing .a slot extending for a definite portion of its peripheral length and a cam follower, the cam follower being adapted to make and' break an electric switch means in the driving motor circuit initially closed by the page framing signal responsive means, saidelectric Aswitch being connected in parallel with another switch circuit, the latter switch being operable to close the' motor circuit by line framing means at definite intervals. r

5. A page and line frame apparatus wherein signals of definite duration'indicative of page and lineI correct positions are transmitted comprising, motor means, means operable upon the 4re- `ceipt of a portion of said page frame signal for initially completing the energizing circuit of said motor means, a recording material, means associated with said material for indicating correct spacing of said pages, means associated with the material feeding apparatus for de-energizing said material feed at intervals determined by the spacing indication associated with said material, and

6. A page and line synchronizing apparatus comprising motor means, a plurality of cams of line configuration, a'portion at least of which are driven at equal angular speeds by said driving motor, a portiony of said cams being mounted in like angular relationship to said motor means, switching means controlled by each of said cams, and means for locking the switching of a plurality of said cams in accordance with the switching of one of said cams.

7. Apage framing system for facsimile apparatus wherein page frame signals of definite duration are transmitted at predetermined intervals comprising, a driving motor, means operable upon the receipt of a predetermined portion less than 8. A page framing system for 'facsimile apparatus wherein page frame signals of definite duration are transmitted at predetermined intervals comprising, a driving motor, means operable upon the receipt of a predetermined portion of each of said page framing signals to initially complete the driving motor energizing circuit, said. means'being adapted to reset itselfv upon' receipt of a portion of said page framing signal of less duration than said predetermined portion, and means for interrupting said driving motor energizing circuit at predetermined intervals in the absence of one of said page framing signals.

' 9. A page frame apparatus for facsimile wherein signals of definite duration indicative of cor' rect page frame position are transmitted comprising, motor means, means operable upon the receipt of predetermined portion of said page framing signals to initially complete the energiz- MAURICE Aa'rzr. so I

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